Double blade hair straightener



FIG. 1 is a perspective view taken from the top of a double blade hair straightener showing my design therefor;

FIG. 2 is a top plan view thereof;

FIG. 3 is a bottom plan view thereof;

FIG. 4 is a side elevational view thereof;

FIG. 5 is a front elevational view thereof; and,

FIG. 6 is a rear elevational view thereof.

The broken lines illustrate portions of the double blade hair straightener and form no part of the claimed design. 

CLAIM The ornamental design for a double blade hair straightener, as shown and described. 